Caloric restriction has been shown in numerous studies in rodents to extend the maximal life span, retard age-associated physiological changes and delay or prevent most age associated disease. If these findings are to be extrapolated to human beings, it will first be necessary to test varying dietary regimens in some higher species and evaluate the effect on an age-related disease process, particularly as it relates to human health. As such, age related disease such as atherosclerosis would be a valuable end point to study. To diminish atherosclerosis, the caloric restriction should alter pathogenic mechanisms contributing to the disease process. Therefore, the proposed research will evaluate a well characterized non -human primate model for human atherosclerosis and study dietary intervention in the form of caloric restriction compared to unrestricted diet with equivalent cholesterol content. We will evaluate for changes secondary to the dietary restriction on insulin resistance, arterial collagen glycation/advanced glycation, and adipose distribution, all of which have been strongly implicated in contributing to cardiovascular disease. The changes in our parameters secondary to dietary intervention, will be related to changes in atherosclerosis assessed at study completion.